I put some oil on the rubber seal (smear over). Then i tighten it by hand and not full strength (since I'm known by a talent for stripping threads). Then I wipe clean round the filter. Fill new oil. Run the bike and see if it leaks. It never does. So it doesn't take much force. As time goes by, when I change oil and take filter off, it is quite hard to undo. Easy on - hard to go off.
So no need to make it too tight. Do it light and check if it leaks when warmed up proper.